Furnace roof suspended by interconnected brick hanger extensions



Jan. 15, 1963 c. R. MONLUX 3,073,264

FURNACE ROOF SUSPENDED BY INTERCONNECTED BRICK HANGER EXTENSIONS Filed March 21, 1960 2 Sheets-Sheet 1 TOR ATTORNEYJ'.

Jan. 15, 1963 c. R. MONLUX 3,073,264

FURNACE ROOF SUSPENDED BY INTERCONNECTED BRICK HANGER EXTENSIONS 2 Sheets-Sheet 2 Filed March 21, 1960' I Clam 5W United States Patent O 3,673,264 FURNACE ROOF SUSPENDED BY HNTERCGN- NE CTED BRICK HANGER EXTENSIONS Claude Richard Moniux, Shaker Heights, Ohio, assignor to General Refractories Company, a corporation of Pennsylvania Filed Mar. 21, 1960, Ser. No. 16,520 1 Claim. (Cl. 11099) The present invention relates to basic refractory bricks and furnace constructions thereof, such as roofs and walls of open hearth furnaces and of electric steelmaking furnaces, and walls of kilns and the like.

The present application is a continuation-in-part of my copending application Serial No. 8,061, filed February 11, 1960, and now abandoned, for Furnace Constru;tion.

A further purpose is to increase the life of basic refractory furnace structures.

A further purpose is to increase the facility of patching basic refractory furnace structures.

A further purpose is to reduce the danger of failure of individual basic refractory bricks in a furnace structure.

A further purpose is to make it easier to support basic refractory constructions such as roofs.

A further purpose is to minimize warpage and buckling of metallic structural elements such as supports and shells of furnaces and the like.

A further purpose is to extend metallic fins at the cold ends of basic refrattory brick.

A further purpose is to separate the cold ends of b ic refractory structures from structural elements and shells of a furnace or the like for a predetermined distance by fins or extensions at the cold end.

A further purpose is to provide hanger extensions at both opposed faces of a basic refractory brick at the cold end and to connect hooks or the like to two hanger extensions of adjoining bricks together.

A further purpose is to interconnect hanger extensions of one brick with the next brick at the cold end.

Further purposes appear in the specification and in the claim.

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a diagrammatic transverse vertical section of an open hearth furnace roof of the invention.

FIGURE 2 is a perspective of a basic refractory brick in accordance with the invention.

FIGURE 3 is a top plan view of the brick of FIG- URE 2.

FIGURE 4 is a section of FIGURE 3 on the line 4-4.

FIGURE 5 is an enlarged fragment of FIGURE 1 showing two bricks adjoining and showing the hanger extension of one brick about to be bent up into service position.

FIGURE 6 is a fragmentary front elevation of a basic refractory brick engaging the shell of an electric furnace or kiln, the shell being sectioned.

FIGURE 7 is a perspective showing a variation in the brick of the invention.

FIGURE 8 is a top plan view of the brick of FIG- URE 7.

FIGURE 9 is a section of FIGURE 8 on the line 9-9.

FIGURE 10 is a front elevation of the brick of FIG- URES 7 to 9 showing a hanger bar in place for hanging the brick in a furnace roof, wall or the like.

Patented Jan. 15, 1963 FIGURE 11 is an enlarged fragmentary side elevation of a hanger extension portion which has a plurality of openings beyond the cold end of the brick to permit better air circulation.

Describing in illustration but not in limitation and referring to the drawings:

Diificulty has been encountered in the prior art in basic refractory brick constructions through the presence of localized hot spots. These have been caused in part by the inability of the refractory to cool effectively at certain points, due to the presence of beams or other structural elements which interfere with effective cooling.

The effect has not only been to reduce the life of the refractory in certain locations, but also in some instances the supporting metallic structure has been damaged by warpage or buckling. This feature has been present particularly in electric furnaces and kilns.

The present invention is designed to provide effective cooling of basic roofs and other parts of open hearth furnaces, and also of basic roofs and other parts of electric steel-making furnaces and rotary kilns.

As a consequence the life of the basic refractory installation is markedly increased.

. The invention also facilitates localized repair or patching. The invention also makes installation easier than would otherwise be possible.

Considering now the drawings in detail, I illustrate in FIGURE 1 a suspended open hearth furnace roof arch 20, which is suitably adjoining but spaced from the tops of the furnace front and back walls 21 and 22.

Arcuate beams 23 extend transversely above the roof and are carried by suitable longitudinal beams not shown, at the front and back, the beams 23 desirably being shaped in the desired arch form. Over the beams 23 extend U- shaped double hook metallic hangers 24, which interconnect with individual bricks of two rows.

The bricks are suitably of wedge 01" key form as desired, and no intention exists to limit in respect to whether certain lateral faces of the bricks taper or are parallel.

Each brick 25 has a body 26 consisting of basic refractory which will suitably be magnesia or a mixture of chromite and magnesia containing at least 10% of magnestia by weight. Any other basic refractory may be used. It is not critical in the present invention whether the basic refractory is of the character which contains more than 55% magnesia and the balance substantially chromite, or is of the type which contains more than 55% of chromite and the balance substantially magnesia. The refractory body may be fired or unfired, although unfired refractory is preferred and is important where comolded oxidizable metallic plates are being used.

The bricks 25 as shown in FIGURES 2 to 5 inclusive have comolded on three adjoining lateral faces a U-shaped oxidizable metallic plate 27 which extends from substantially the hot end 28 to substantially the cold end 30 as shown. The U-shaped plate suitably has thus one broad plate portion 31 on a wide side face and two narrower plate portions 32 on narrower side faces, there being tabs 33 projecting from the plate portions 32 and comolded in the refractory brick. The U-shaped external plate 27 is united as by welding at 34 to a U-shaped internal plate 35 which has the base of the U 36 secured to the external plate and the arms of the U 37 extending through the body of the refractory in comolded relation to the refractory from substantially the hot end to the cold end, and located about one-third of the brick thickness from each outside plate portion 32 parallel thereto. A separate oxidizable metallic plate 38 is desirably applied to the outside of the brick on the side remote from the base 31 of the U of the plate 30 and has tabs 40 which extend inwardly and are united to the basic refractory by comolding.

Each of the oxidizable metallic plates thus far described will suitably be made of steel such as plain carbon steel or low allow steel or corrosion resisting steel, as desired, but the character of steel should be such as will oxidize at the temperature of use. The thickness of the plates should preferably be in the range between and inch.

At the position adjacent the cold end, the plate portions 32 on-the narrow sides of the brick are uni-ted as by welding at 41 to hanger extension portions 42 which may be initially bent down to rest doubled over against the narrow side of the brick during manufacture and shipment, and then will be reversely bent upward as suggested by the arc 43 (FIGURE 5) at the time of shipment.

The composition of the hanger extensions 42 is desirably corrosion resistant steel such as the straight chromium stainless steel commonly containing 16% by weight of chromium,or the chromium nickel stainless steel commonly containing 18% by Weight of chromium and 8% by weight of nickel. Since these tabs are at the cold end, the corrosion resisting steel will not oxidize during use in an open hear-thfurnace or the like. These corrosion resisting steels may be classified as containing more than 14% chromium, permissibly nickel, permissibly molybdenum, permissibly 'columbium, balance substantially iron.v If desired, however, plain carbon steel can used for the hanger extensions 42. 7

Each of the hanger extensions has near its upper end a hanger opening 44,'and at one side there is provided, suitably from the material lanced out to make the hanger opening, a hook 45 which as shown in FIGURE 5 is adapted to connect into the upper portion of the hanger opening 44 of the next refractory brick.

The lower hook ends of the metallic hangers 24 extend through the openings 44 of the hanger extensions 42 of two bricks and extra assurance of support is provided by the hook 45.

The internal plates at the sides of the U extend beyond the cold end of the brick to form fins 46, the extension desirably being as far up as the upper ends of the hanger extensions 42 when the hanger extensions are extended upward. The hanger extensions 42 and the fins 46 are parallel. To provide for the possibility that a hanger bar will be used as in FIGURE 10, openings 47 are provided in the fins in line with the hanger openings 44 in the hanger extensions.

It will thus be evident that in the construction of FIG- URES 1 to 5 inclusive which will. suitably be an open hearth furnace roof, the fins 46 have metal to metal interconnection with the U-shaped external plate structure and assist in carrying heat to the cold end and dissipating that heat to air at the cold end, notwithstanding any insulating eliect which may be caused on the cold end by the usual deposit of graphite and dust.

Due to the fins it will not be possible to place the cold end of the brick directly against a hold-down beam, and therefore the tendency which has previously been encountered to overheat and lower the life of the roof from th's cause will be avoided.

The construction of the invention is very simple to install, merely requiring connecting the hook ends of the metallic hangers 24 into the openings of the hanger extensions. The'presence of the hook 45 facilitates support of the adjoining brick, and permits the support of one brick and an adjoining brick by a hanger bar as'shown in FIGURE 10.

It will be evident as shown in FIGURE that the hook 45 is desirably placed as shown out of line with the center of the opening so. that the hanger bar 51 can pass through the openings in line with one another without interference with the hook.

Patching of the roof according to the present invention is very easily accomplished.

In order to illustrate the versatility of the invention, 1 illustrate in FIGURE 1 hangers 24 for every brick atthe right in FIGURE 1, but at the left every alternate brick hangs from the book 45 of the next brick, and hangers 24 are applied to each alternate brick in the same transverse row.

The use of the brick of the invention in preventing localized hot zones adjoining supporting structure such as a beam or the shell of the furnace is illustrated in FIG- URE 6. In FIGURE 6 the metallic shell 43 of an electric furnace is engaged by the ends of the fins 46 and the ends of the extensions 42, thus protecting the shell against direct contact with the cold end of the brick and guarding against Warpage or buckling. It will be evident of course that air can be circulated into space between the refractory and the shell or that if desired openings can be provided in the shell to aid in cooling. This applies also in the case of rotary kilns.

The principles of the invention can be applied to a brick that does not have internal plates as shown in FIGURES 7 to 10 inclusive. In this instance the base of the U 31 of the external plate is extended beyond the cold end at 50 to provide a cooling and spacing fin and the hanger extensions are provided as previously explained.

A hanger bar 51 is carried through the openings 44 in the hanger extensions 42 of a number of bricks and the bars 51 are suitably supported as by hooks. At one end of a group of bricks the last brick hanger extension beyond the bar 51 is suitably provided with a book 45 for engagement in the hanger opening 44 of the adjoining brick.

In some cases it may be preferable to use a plurality of openings in the extensions 42. In FIGURE 11 I show an extension 42 which beyond the cold end of the brick has a relatively large opening 44 and several smaller openings-44', thus permitting more eifective air circulation.

In view of my invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claim.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is:

A furnace roof construction comprising basic refractory bricks having bodies of basic refractory, oxidizable metallic plates of continuous solid metal on the brick extending out beyond the cold ends of the refractory on two opposed faces of each brick, there being an opening in said extension at the cold end on one side of each brick, there being a hook on the extension beyond the cold end at the other side of each brick which engages in said opening of the next brick, all of said extensions being generally parallel to one another, and hanger means interconnected with the opening in the extension beyond the cold end at the one side of each alternate brick, said hanger means supporting said alternate brick directly and supporting the next brick by means of. said hook.

References Cited in the file of this patent UNITED STATES PATENTS 2,476,423 Longenecker July 19, 1949 2,781,006 Heuer Feb. 12, 1957 2,932,265 Heuer Apr. 12, 1960 FOREIGN PATENTS 638,767 Great Britain June 14, 1950 1,035,154 France Apr. 15, 1953 690,898 Great Britain Aug. 29, 1958 

